What every patient needs to know about biosimilars

Biosimilars in brief biosimilars in brief

A quick guide to biosimilar medicines, how they are made, and why you can trust them to be safe and effective.

If you have been prescribed a biosimilar medicine, you probably have lots of questions. Because, like most people, it is unlikely you have heard of the term before. That is because it is a relatively new area of medicine, but one that will become more common in the future.

What are biosimilar medicines?

Unlike chemical medicines, biological medicines like biosimilars come from living cells. These cells are modified so that they produce active substances that can be harvested and used to treat a wide range of conditions.

The reason why biosimilars can be prescribed is because they are highly similar to an existing biological medicine, known as the reference medicine, which has already been approved as an effective treatment. Once the exclusive patent of the reference medicine has expired, biosimilar versions are allowed on the market.

What we mean by highly similar is that the two medicines are essentially the same with slight differences being allowed, because also the reference medicine will have variations which are however not clinically meaningful. Even the reference medicine will have variations of different parameters, which are not clinically meaningful. The key thing to remember is that the differences between biosimilar and reference drug are kept within very strict limits to guarantee both drugs will work in the same way.

How are they approved?

Any scientific knowledge gained from the reference medicine is applied to the biosimilar medicine. This means, it is not always necessary to repeat clinical studies for all the conditions the reference medicine has been shown to work. Instead, the safety and efficacy data from one condition can be extrapolated to cover other indications. If any studies are carried out, it is usually to demonstrate biosimilarity. In other words, that there is no clinically-meaningful difference between the two drugs.

Biosimilars must be evaluated by the European Medicines Agency (EMA) before they can be approved for use. Like any medicine, it must be shown that the benefits outweigh the risks. This involves extensive laboratory studies with the reference medicine to compare its structure and function and may involve human clinical studies. If these prove to be positive, the biosimilar medicine will be approved for use by the EMA.

Are they safe and effective?

When used appropriately for the conditions they are approved to treat, biosimilar medicines are safe and effective. But as with any medicine, make sure you talk to your doctor about all the treatment options that are available to you so you can compare their benefits and risks.

If you would like more in-depth information about the biosimilar you have been prescribed, please search the EMA website.